The Magnificent Migrating Monarch: By Pat Schuler

Submitted by Tom Wilmoth on Fri, 12/16/2011 - 5:15pm

When I visited "The Butterfly Farm Costa Rica" this last March, I learned that Central Amerca has its own population of Monarchs, as well as some of the Monarch "mimics", such as the Queen butterfly. However, their Monarchs don't migrate. In fact, a little research revealed that this butterfly is tropical in its distribution, perhaps even originating as a tropical species. Only in North America does it make the amazing journeys from Mexico to Canada and back again. Although Monarchs are longer lived than most butterflies, this is too long a migration for any single individual. However, what they do is even more wonderful than that would be. As they travel north in the spring from their wintering forests in Mexico or southern California, They leave eggs behind them on the milkweed plants – the necessary food for their caterpillars to eat and grow on. The eggs hatch into brightly colored caterpillars, which feed hungrily on the leaves of the plants selected by their mothers, who have already continued on their way north to Canada.

After growing out of their caterpillar skins several times, they shed the last skin and emerge as jade green chrysalides beautifully decorated with shiny gold beads. While it hangs tail end up from a nearby plant or other surface, one of God's miracles is taking place inside what would first appear to be the caterpillar's coffin. Inside that tiny box, the caterpillar's body is being torn apart and reassembled into a lovely replica of its parents. Soon it will break free, expand and dry its new wings. Then it will take off on its maiden flight, following its parents on their journey. Continuing this amazing saga, those butterflies which reach the northernmost part of their migration will leave behind them offspring which, as fall approaches, will now travel down the eastern part of the U.S. on a return flight to Mexico! As they travel, they must also leave behind them larvae which need milkweed for food. The trip is so long that it takes approximately four generations to complete the entire round trip!

When they reach Mexico (or Southern California for those West of the Rocky Mts.) they congregate in just a few forests, returning to the areas their grandparents had left the previous spring. There they hang from the trees, occasionally rising to fly a short distance on warm, sunny, days. For the entire winter they wait until, with the arrival of spring, they will begin the entire cycle again.
No other butterfly, anywhere in the world, does anything like this migration which we are privileged to observe in North America. Sadly, though, we may be coming to the end of this wonderful experience unless we act to save the plants which sustain it. I'll have more to say about that,and what you can do, in my next post.